C-8530 Phosphate, ortho Comparator is a component of K-8530 Phosphate, ortho CHEMets Visual Test Kit and is designed to be compared against the color formed in R-8515 Phosphate CHEMets Refill. The comparator's range is applicable to many industrial applications. Color standards are yellow in color and cover a range of 2 to 30 ppm PO₄.